This name is a synonym of Petasites japonicus (Siebold & Zucc.) Maxim..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 08081261-126D-45F0-9E8D-0590A3811832) with original publication details: "Flora Japonica, . . ." 314 1784.
This name was in version 1 of The Plant List, record gcc-2999.